CN201120278Y

CN201120278Y - Microreactor for continuously synthesizing inorganic nanocrystalline

Info

Publication number: CN201120278Y
Application number: CNU2007200765028U
Authority: CN
Inventors: 栾伟玲; 杨洪伟; 涂善东
Original assignee: East China University of Science and Technology
Current assignee: East China University of Science and Technology
Priority date: 2007-11-07
Filing date: 2007-11-07
Publication date: 2008-09-24
Anticipated expiration: 2017-11-07

Abstract

The utility model relates to a micro-reactor which can achieve continuous synthesis of inorganic nanocrystals. The entire synthesis device is composed of a sample introduction system, a micro-mixer, a micro-channel and a heating component and has the advantages that firstly, the micro-mixer makes use of the convective mass transfer caused by magnetic force stirring to realize high-performance mixing of liquid in low flow velocity; secondly, the realization means of the micro-channel is flexible and changeable; thirdly, the obtained nanocrystals have narrow size distribution; fourthly, controllability and continuous synthesis of nanocrystals can be achieved. With only the types of precursors being changed, the micro-synthesizer can be widely used for continuous preparation of various inorganic nanocrystals; at the same time, the increase of parallel micro-channels and the prolongation of operation time are helpful for large-scale preparation of inorganic nanocrystals. In addition, the portability of the entire synthesis system can meet the needs of flexible production.

Description

A kind of micro-reaction device of continuous synthetizing inorganic nanocrystal

Technical field

The utility model relates to a kind of micro-reaction device that can realize that inorganic nano-crystal is continuously synthetic, has good stability, obtains the product quality height, cost is low, the characteristics of high flexible; Belong to little chemical machinery and field of inorganic nonmetallic material.

Background technology

Along with the protrusion day by day of ecological environment and energy problem, the high energy consumption that traditional chemical reaction device produces, high pollution constitute grave danger to the human existence space.The microminiaturization of chemical reaction device will directly cause the reduction of energy consumption and the raising of security, extremely strong heat and mass transfer efficient more can realize the High-efficient Production of number of chemical product under the microenvironment simultaneously, thereby makes the many fields relevant with chemical process produce revolutionary variation.

Inorganic nano-crystal has excellent photoelectricity, thermoelectricity and magnetic property, show unique advantage at aspects such as drug screening, biomarker, medical imagings, apply it to fields such as light emitting diode and sensor, solar cell, laser, optic communication, infrared acquisition and also will bring subversive progress.A large amount of acquisitions of high-quality inorganic nano-crystal are to carry out related science research and the basis of using, and the research of inorganic nano-crystal synthesizer has become the problem of scientific circles' extensive concern.

The organic metal high temperature pyrolytic cracking (HTP) of carrying out in the flask synthesizer at present, has become the successful example of preparation inorganic nano-crystal.Yet the flask synthesizer intrinsic control accuracy poor, temperature control response slow and deficiency such as intermittent operation reduces the repeatability of synthetic reaction greatly, causes the different operating personnel to use same device can not obtain product identical in quality.In addition, the direct amplification of this type of synthesizer physical dimension will make its control accuracy and control response time further worsen, and therefore be difficult to a large amount of productions that realize that high-quality is nanocrystalline.

The utility model content

The purpose of this utility model is the synthetic micro-reaction device of exploitation inorganic nano-crystal, with the low cost that realizes the inorganic fluorescence nano of high-quality, fast, efficient, can repeat and produce continuously.

Key problem in technology of the present utility model is to adopt the magnetic force convection current of (volume 30～100 microlitres) in the minute yardstick space mix to realize the efficient mixing of following two strands even multiply raw material of low flow conditions, use the instantaneous forming core in the heat-transfer character realization inorganic nano-crystal building-up process that fluid is exceedingly fast in the micro-tube simultaneously, and make the fluid that flows out heating region be cooled to room temperature at short notice, the accurate control of realization response time; And develop continuous little synthesizer that cost is low, stability is high, flexibility is good by each functional unit integrated, with realize many sizes, singly disperse, the high-crystallinity inorganic nano-crystal synthetic continuously.

The utility model is achieved through the following technical solutions:

A kind of micro-reaction device of continuous synthetizing inorganic nanocrystal, it is characterized in that, described device comprises to sample system, micro-mixer, reaction system and collection container, liquid storage container 1 links to each other with micro-injection pump 2 and constitutes the sample system that gives, and converges back access micro-mixer 3 by the outlet conduit of micro-injection pump 2 for the sample system by at least two groups; Reaction system is a stable thermal source 7 and places micro-tube 5 on the stable thermal source 7, the two ends of micro-tube 5 respectively respond import 4 and reaction outlet 6; Micro-mixer 3 links to each other with reaction system by reaction inlet 4, and reaction exports 6 and links to each other with collection container 8;

Wherein, said micro-tube is the smooth pipeline of inner surface of 0.2～0.5mm for the equivalent internal diameter.

The further improved technical scheme of the utility model is as follows:

Reaction system in the said apparatus is an electric tube furnace 14, stainless steel stay pipe 16 places the center of stove along the axis of electric tube furnace, and the two ends of stay pipe 16 place micro-tube 5 in the stay pipe 16 with heat insulation 17 sealings, micro thermocouple 15 is inserted in stay pipe 16 surperficial perforates.

Micro-mixer 3 in the said apparatus is: one places the miniature vessel 11 on the magnetic stirring apparatus 9 to be built-in with a magnetic stirring bar 13, be provided with micro-mixer import 10 in the bottom of miniature vessel 11 and link to each other for the sample system, the top is provided with micro-mixer and exports 12 and link to each other with reaction system.

This little synthesizer is seen figure one by forming for sample system, micro-mixer, reaction system and collection container.The sampling system that is made of liquid storage container 1 and micro-injection pump 2 imports micro-mixer 3 with reaction mass; Micro-mixer is by miniature liquid storage container and the little bar construction of magnetic, and the convective mass transfer that magnetic agitation causes can the efficient mixing of realization response material under low flow conditions; Mixed material heats in stable thermal source 7, the heat transfer efficiency that is exceedingly fast in the micro-tube with material in short-term (＜1s) be heated to target temperature rapidly, to realize the instantaneous formation of nanocrystal, under stationary temperature, realize nanocrystalline growth then; The synthetic product of outflow conversion zone is reduced to room temperature rapidly makes the reaction cancellation, but the accurate control by changing the sample introduction flow velocity and heating the length realization response time of micro-tube.

Beneficial effect

Convection current in the utility model uses between microvoid mixes the efficient mixing that has realized fluid under the low flow conditions, and accomplished in many ways can be passed through in the microchannel that relates in the utility model, both can use the passage of micro-machined method etching appropriate size on different matrix, also can select the microchannel of various material for use according to the difference of reaction temperature.By the accurate control of reaction time and reaction temperature, can realize the controlled, synthetic continuously of multiple high-quality inorganic nano-crystal; Simultaneously, the increase of Bing Hang microchannel number and the prolongation of operating time all help the fairly large preparation of inorganic nano-crystal; In addition, the portable characteristics of entire reaction system can satisfy the needs of flexible production.

Description of drawings

Fig. 1 is the structure diagram of the synthetic little reaction system of inorganic nano-crystal,

Wherein, 1-liquid storage container; The 2-micro-injection pump; The 3-micro-mixer; The 4-reaction inlet; 5-micro-tube (equivalent internal diameter 0.2-0.5mm); 6-reacts outlet; The thermal source that 7-is stable; The 8-collection containers.

Fig. 2 is the profile of improved nanocrystalline synthetic micro-reaction device,

Wherein, 1-liquid storage container; The 2-micro-injection pump; The 3-micro-mixer; The 4-reaction inlet; 5-micro-tube (equivalent internal diameter 200-500 μ m); 6-reacts outlet; The thermal source that 7-is stable; The 8-collection containers, the import of 9-magnetic stirring apparatus 10-micro-mixer; The 11-miniature vessel; The outlet of 12-micro-mixer; The little rod of 13-magnetic force; The 14-electric tube furnace; The 15-micro thermocouple; 16-stainless steel stay pipe; The 17-heat insulation.

Fig. 3 changes the influence of the time of staying to the nanocrystalline absorption spectrum of CdSe.

Fig. 4 changes the influence of reaction temperature to the nanocrystalline absorption spectrum of CdSe.

Fig. 5 is nanocrystalline UV-Vis absorption spectrum and a fluorescence spectrum of CdSe.

Fig. 6 is the nanocrystalline TEM photo of CdSe.

The specific embodiment

Below by embodiment the utility model is further elaborated, but does not limit protection domain of the present utility model.

Embodiment (nanocrystalline the synthesizing of CdSe):

(1), nanocrystalline to CdSe, various proportion of raw materials satisfy the mol ratio of following proportionate relationship: Se and CdO=5: 1, the mol ratio of oleic acid and CdO=10: 1, and tri-n-octyl phosphine and Se mol ratio=4: 1; Prepare Se, Cd presoma according to the above ratio respectively, and use octadecylene and oleyl amine to be diluted to equal-volume, outgased 1 hour down, in the syringe of the strict sealing of packing into then at 100 ℃;

(2) Ni base magnetic force little excellent 13 being placed volume is in the polytetrafluoroethylcontainer container 11 of 80ml, constitutes micro-mixer.Container bottom and top are provided with solution inlet port and outlet respectively, and place on the common magnetic stirring apparatus 9; Use polyfluortetraethylene pipe to connect syringe, micro-mixer, micro-tube, guarantee strict sealing.Polytetrafluoroethylene (PTFE) microtubule 5 is placed in the thin stainless steel tube, and stainless steel tube is placed on the center of furnace chamber along the axis of tube furnace, and the strict sealing of heat-insulating material is used at two ends; Micro thermocouple 15 is inserted in the stainless steel pipe surface perforate, sees Fig. 2.Open tube furnace 14, slowly heat up (5 ℃ of per minutes), treat that the stable back of furnace temperature (variation of micro thermocouple reading in 10min is no more than 0.5 ℃) starts syringe pump;

(4) the flow velocity control solution of adjusting micro-injection pump 2 is regulated the temperature of tube furnace, to obtain the nanocrystalline of required size in the time of staying of bringing-up section.The sample that collect in exit 6 absorbs with fluorescence spectrum to be tested.Find by test, under 285 ℃, will the time of staying change to 30s and can cause the nanocrystalline absorption spectrum of CdSe remarkable red shift to occur, and minimum of a value appears in the half width at half maximum of absworption peak under the specific time of staying (20s 17nm), sees Fig. 3 from 5s.Reaction temperature also produces appreciable impact to the particle diameter of CdSe and Size Distribution, and the synthetic down CdSe of higher temperature is nanocrystalline to have bigger particle diameter and narrower Size Distribution, sees Fig. 4.By adopting optimum reaction time (20s) and reaction temperature (285 ℃), can realize that nanocrystalline (synthesizing continuously of fluorescence spectrum half-peak breadth～35nm) seen figure five, Fig. 6 to high-quality CdSe.In addition, only need change the sample introduction ratio of Se presoma and cadmium presoma, can realize the preparation that serial size CdSe is nanocrystalline.

Claims

1, a kind of micro-reaction device of continuous synthetizing inorganic nanocrystal, it is characterized in that, described device comprises to sample system, micro-mixer, reaction system and collection container, liquid storage container (1) links to each other with micro-injection pump (2) and constitutes the sample system that gives, and converges back access micro-mixer (3) by the outlet conduit of micro-injection pump (2) for the sample system by at least two groups; Reaction system is a stable thermal source (7) and places micro-tube (5) on the stable thermal source (7), the two ends of micro-tube (5) respectively respond import (4) and reaction outlet (6); Micro-mixer (3) links to each other with reaction system by reaction inlet (4), and reaction outlet (6) links to each other with collection container (8); Wherein, said micro-tube (5) is the smooth pipeline of inner surface of 200～500 μ m for the equivalent internal diameter.

2, little synthesizer of a kind of continuous preparation inorganic nano-crystal as claimed in claim 1, it is characterized in that, reaction system in the described device is: an electric tube furnace (14), a stainless steel stay pipe (16) places the center of stove along the axis of electric tube furnace, the two ends of stay pipe (16) seal with heat insulation (17), micro-tube (5) is placed in the stay pipe (16), and micro thermocouple (15) is inserted in the surperficial perforate of stay pipe (16).

3, little synthesizer of a kind of continuous preparation inorganic nano-crystal as claimed in claim 1 or 2, it is characterized in that, micro-mixer in the described device (3) is: one places the miniature vessel (11) on the magnetic stirring apparatus (9) to be built-in with the little rod of a magnetic force (13), be provided with micro-mixer import (10) in the bottom of miniature vessel (11) and link to each other with giving the sample system, the top is provided with micro-mixer outlet (12) and links to each other with reaction system.